In a program we use Oracle Advanced Queueing OCI calls to communicate with other programs. For reading messages we use the OCIAQDeq function. When this function returns an error we re-initialize the communication channel and try to re-read from it. However, such a re-read returns an error code ORA-21779. When looking up this code, it only says "duration not active - an attempt was made to use a duration that has been terminated". Does anyone know what is meant with this message and where 'duration' refers to?